Note that the values represent normal production practice at the most economical level. Greater accuracy should only be specified where required to avoid additional costs.

Parting line tolerances

Parting line tolerances, in addition to Linear dimensional tolerances, must provide for the movement of the die. The "Projected Area" is the area of the diecasting in square centimetres at the parting plane.

Additional
Tolerance in Millimetres

Projected
Area of
Diecasting in cm2

Diecasting
Alloy

Zinc

Aluminium

Magnesium

Up to 325 cm2

+/- 0.10

+/- 0.13

+/- 0.13

325 to 650 cm2

+/- 0.15

+/- 0.20

+/- 0.20

650 to 1,300 cm2

+/- 0.20

+/- 0.30

+/- 0.30

1,300 to 2,000 cm2

+/- 0.30

+/- 0.40

+/- 0.40

Moving Die Part Tolerances.

Moving die part tolerances, in addition to Linear dimensional tolerances must be provided when a moving die part affects the dimension. The "Projected Area" is the area, in square centimetres of the portion of the diecasting affected by the moving die part.

Additional
Tolerance in Millimetres

Projected
Area of
Diecasting in cm2

Diecasting
Alloy

Zinc

Aluminium

Magnesium

Up to 65 cm2

+/- 0.10

+/- 0.13

+/- 0.13

65 to 130 cm2

+/- 0.15

+/- 0.20

+/- 0.20

130 to 325 cm2

+/- 0.20

+/- 0.30

+/- 0.30

325 cm2 and Upwards

+/- 0.30

+/- 0.40

+/- 0.40

Tolerance for Flatness.

The flatness should be measured with a feeler gauge from three widely separated points on a continuous plane surface of the diecasting. In the table below, "Dimension" means the maximum dimension (Diameter of a circular surface or diagonal of a rectangular surface.)